-- Verwaiste Verweise vor dem Setzen der Foreign Keys auf NULL bereinigen — sonst
-- schlaegt ADD CONSTRAINT fehl, falls Altdaten auf geloeschte Zeilen zeigen.
UPDATE "blocker" SET "area_id" = NULL WHERE "area_id" IS NOT NULL AND "area_id" NOT IN (SELECT "id" FROM "area");--> statement-breakpoint
UPDATE "blocker" SET "project_id" = NULL WHERE "project_id" IS NOT NULL AND "project_id" NOT IN (SELECT "id" FROM "project");--> statement-breakpoint
UPDATE "day_entry" SET "blocker_id" = NULL WHERE "blocker_id" IS NOT NULL AND "blocker_id" NOT IN (SELECT "id" FROM "blocker");--> statement-breakpoint
ALTER TABLE "blocker" ADD CONSTRAINT "blocker_area_id_area_id_fk" FOREIGN KEY ("area_id") REFERENCES "public"."area"("id") ON DELETE set null ON UPDATE no action;--> statement-breakpoint
ALTER TABLE "blocker" ADD CONSTRAINT "blocker_project_id_project_id_fk" FOREIGN KEY ("project_id") REFERENCES "public"."project"("id") ON DELETE set null ON UPDATE no action;--> statement-breakpoint
ALTER TABLE "day_entry" ADD CONSTRAINT "day_entry_blocker_id_blocker_id_fk" FOREIGN KEY ("blocker_id") REFERENCES "public"."blocker"("id") ON DELETE set null ON UPDATE no action;